High output battery modules using, e.g., a non-aqueous electrolyte of high energy density, have been developed. The high output battery module may include a plurality of battery cells connected in series to drive a machine with a high power, e.g., to drive a motor of an electric automobile.
The plurality of battery cells in the battery module may transfer energy to an external electronic device using an electrochemical reaction. In this case, the battery cells may each generate heat during the electrochemical reaction, and when the heat is accumulated, the battery cells may be degraded. In severe cases, a safety problem may occur due to the heat. Therefore, various studies have been made to control a temperature of the battery cells.